641151720 has 256 divisors, whose sum is σ = 2413152000. Its totient is φ = 149990400.

The previous prime is 641151697. The next prime is 641151781. The reversal of 641151720 is 27151146.

It is a happy number.

641151720 is a `hidden beast` number, since 641 + 1 + 5 + 17 + 2 + 0 = 666.

641151720 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×641151720² = 822151056117916800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 343590 + ... + 345450.

It is an arithmetic number, because the mean of its divisors is an integer number (9426375).

Almost surely, 2^641151720 is an apocalyptic number.

641151720 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 641151720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1206576000).

641151720 is an abundant number, since it is smaller than the sum of its proper divisors (1772000280).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

641151720 is a wasteful number, since it uses less digits than its factorization.

641151720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1921 (or 1911 counting only the distinct ones).

The product of its (nonzero) digits is 1680, while the sum is 27.

The square root of 641151720 is about 25320.9739149188. The cubic root of 641151720 is about 862.2905048848.

The spelling of 641151720 in words is "six hundred forty-one million, one hundred fifty-one thousand, seven hundred twenty".